drm: Make DrmDisplayHostManager handle VGEM fd by itself.

ui/ozone/platform/drm/host/drm_display_host_manager.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_OZONE_PLATFORM_DRM_HOST_DRM_DISPLAY_HOST_MANAGER_H_
 #define UI_OZONE_PLATFORM_DRM_HOST_DRM_DISPLAY_HOST_MANAGER_H_
 
 #include <queue>
 #include <set>
 
-#include "base/files/file_path.h"
+#include "base/files/scoped_file.h"
 #include "base/memory/scoped_vector.h"
 #include "base/memory/weak_ptr.h"
 #include "ui/display/types/native_display_delegate.h"
 #include "ui/events/ozone/device/device_event.h"
 #include "ui/events/ozone/device/device_event_observer.h"
 #include "ui/ozone/public/gpu_platform_support_host.h"
 
 namespace ui {
 
 class DeviceManager;
@@ skipping 66 matching lines @@
   DrmGpuPlatformSupportHost* proxy_;  // Not owned.
   DeviceManager* device_manager_;     // Not owned.
 
   DrmNativeDisplayDelegate* delegate_;  // Not owned.
 
   // File path for the primary graphics card which is opened by default in the
   // GPU process. We'll avoid opening this in hotplug events since it will race
   // with the GPU process trying to open it and aquire DRM master.
   base::FilePath primary_graphics_card_path_;
 
+  // File path for virtual gem (VGEM) device.
+  base::FilePath vgem_card_path_;
+
   // Keeps track if there is a dummy display. This happens on initialization
   // when there is no connection to the GPU to update the displays.
   bool has_dummy_display_;
 
   ScopedVector<DrmDisplayHost> displays_;
 
   GetDisplaysCallback get_displays_callback_;
 
   // Used to serialize display event processing. This is done since
   // opening/closing DRM devices cannot be done on the UI thread and are handled
   // on a worker thread. Thus, we need to queue events in order to process them
   // in the correct order.
   std::queue<DisplayEvent> event_queue_;
 
   // True if a display event is currently being processed on a worker thread.
   bool task_pending_;
 
   // Keeps track of all the active DRM devices.
   std::set<base::FilePath> drm_devices_;
 
   // This is used to cache the primary DRM device until the channel is
   // established.
   scoped_ptr<DrmDeviceHandle> primary_drm_device_handle_;
 
+  // Manages the VGEM device by itself and doesn't send it to GPU process.
+  base::ScopedFD vgem_card_device_file_;
+
   base::WeakPtrFactory<DrmDisplayHostManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DrmDisplayHostManager);
 };
 
 }  // namespace ui
 
 #endif  // UI_OZONE_PLATFORM_DRM_HOST_DRM_DISPLAY_HOST_MANAGER_H_